A light emitting device, for example, a light emitting diode, is a semiconductor device which converts electrical energy into light, and is receiving attention as a next-generation light source to replace conventional fluorescent lamps and incandescent lamps.
The light emitting diode generates light using a semiconductor device, thus causing very low power consumption as compared with an incandescent lamp generating light by heating tungsten or a fluorescent lamp generating light by irradiating ultraviolet light generated through high intensity discharge upon phosphors.
Further, the light emitting diode generates light using a potential gap of the semiconductor device, thus having a long lifespan and fast response time and being environmentally friendly as compared with conventional light sources.
Accordingly, considerable research efforts have focused upon developing light emitting diodes that can replace conventional light sources and light emitting diodes are increasingly used as light sources of lighting apparatuses, such as various lamps used indoors and outdoors, liquid crystal display devices, electric display boards, streetlights and so on.